From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BDE0C433EF for ; Thu, 17 Mar 2022 02:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351756AbiCQCiK (ORCPT ); Wed, 16 Mar 2022 22:38:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231233AbiCQCiI (ORCPT ); Wed, 16 Mar 2022 22:38:08 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5541D64D7 for ; Wed, 16 Mar 2022 19:36:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647484612; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZhwNgQbbAAh7E0gC5xHfd78zBYBbrLsvzLXwX0m2k0o=; b=iUIMfZizxmSyM286KM1aHrOkruzmL/YWzTqpUQmTkH8WG/uUjNqsfXvqlcssLzzgvNSwKh fkGVhgJG8MI7QU96thypiKENLGZ14qZbdCCzb4Zqxfrhu0PmUVog46Bq/0q6/FaESPIcxs Acp8goECf65Qx/wlYqOsNPkFRlJdQa8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-267-n9NDOC7VOrmT60TGaq6cJg-1; Wed, 16 Mar 2022 22:36:49 -0400 X-MC-Unique: n9NDOC7VOrmT60TGaq6cJg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2141B899EC2; Thu, 17 Mar 2022 02:36:48 +0000 (UTC) Received: from localhost (ovpn-13-190.pek2.redhat.com [10.72.13.190]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 379F230BBC; Thu, 17 Mar 2022 02:36:43 +0000 (UTC) Date: Thu, 17 Mar 2022 10:36:40 +0800 From: Baoquan He To: "Leizhen (ThunderTown)" Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org, Dave Young , Vivek Goyal , Eric Biederman , kexec@lists.infradead.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , John Donnelly , Dave Kleikamp Subject: Re: [PATCH v21 3/5] arm64: kdump: reimplement crashkernel=X Message-ID: References: <20220227030717.1464-1-thunder.leizhen@huawei.com> <20220227030717.1464-4-thunder.leizhen@huawei.com> <7d7a3e70-6a46-b722-ef48-7206a47185dd@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d7a3e70-6a46-b722-ef48-7206a47185dd@huawei.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/16/22 at 09:11pm, Leizhen (ThunderTown) wrote: > > > On 2022/3/16 20:11, Baoquan He wrote: > > On 02/27/22 at 11:07am, Zhen Lei wrote: ...... > > Hi leizhen, > > > > I made change on reserve_crashkenrel(), inline comment may be slow. > > Please check and consider if they can be taken. > > That's great. Thank you very much. > > > > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > index 30ae6638ff54..f96351da1e3e 100644 > > --- a/arch/arm64/mm/init.c > > +++ b/arch/arm64/mm/init.c > > @@ -109,38 +109,43 @@ static int __init reserve_crashkernel_low(unsigned long long low_size) > > * This function reserves memory area given in "crashkernel=" kernel command > > * line parameter. The memory reserved is used by dump capture kernel when > > * primary kernel is crashing. > > + * > > + * NOTE: Reservation of crashkernel,low is special since its existence > > + * is not independent, need rely on the existence of crashkernel,high. > > + * Hence there are different cases for crashkernel,low reservation: Considering to update the 3rd line as below: * NOTE: Reservation of crashkernel,low is special since its existence * is not independent, need rely on the existence of crashkernel,high. * Here, four cases of crashkernel,low reservation are summarized: > > + * 1) crashkernel=Y,low is specified explicitly, crashkernel,low takes Y; > > + * 2) crashkernel=,low is not given, while crashkernel=,high is specified, > > + * take the default crashkernel,low value; > > + * 3) crashkernel=X is specified, while fallback to get a memory region > > + * in high memory, take the default crashkernel,low value; > > + * 4) crashkernel='invalid value',low is specified, failed the whole > > + * crashkernel reservation and bail out. > > */ > > static void __init reserve_crashkernel(void) > > { > > unsigned long long crash_base, crash_size; > > unsigned long long crash_low_size; > > unsigned long long crash_max = CRASH_ADDR_LOW_MAX; > > - int ret; > > bool fixed_base, high = false; > > char *cmdline = boot_command_line; > > + int ret; > > > > /* crashkernel=X[@offset] */ > > ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), > > &crash_size, &crash_base); > > if (ret || !crash_size) { > > - /* crashkernel=X,high */ > > ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); > > if (ret || !crash_size) > > return; > > > > - /* crashkernel=Y,low */ > > ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); > > if (ret == -ENOENT) > > - /* > > - * crashkernel=Y,low is not specified explicitly, use > > - * default size automatically. > > - */ > > + /* case #2 of crashkernel,low reservation */ > > crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; > > else if (ret) > > - /* crashkernel=Y,low is specified but Y is invalid */ > > + /* case #4 of crashkernel,low reservation */ > > return; > > > > - /* Mark crashkernel=X,high is specified */ > > high = true; > > crash_max = CRASH_ADDR_HIGH_MAX; > > } > > @@ -148,7 +153,6 @@ static void __init reserve_crashkernel(void) > > fixed_base = !!crash_base; > > crash_size = PAGE_ALIGN(crash_size); > > > > - /* User specifies base address explicitly. */ > > if (fixed_base) > > crash_max = crash_base + crash_size; > > > > @@ -172,11 +176,7 @@ static void __init reserve_crashkernel(void) > > } > > > > if (crash_base >= SZ_4G) { > > - /* > > - * For case crashkernel=X, low memory is not enough and fall > > - * back to reserve specified size of memory above 4G, try to > > - * allocate minimum required memory below 4G again. > > - */ > > + /* case #3 of crashkernel,low reservation */ > > if (!high) > > crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; > > > > > >> > >> - /* Current arm64 boot protocol requires 2MB alignment */ > >> - crash_base = memblock_phys_alloc_range(crash_size, SZ_2M, > >> +retry: > >> + crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, > >> crash_base, crash_max); > >> if (!crash_base) { > >> + /* > >> + * Attempt to fully allocate low memory failed, fall back > >> + * to high memory, the minimum required low memory will be > >> + * reserved later. > >> + */ > >> + if (!fixed_base && (crash_max == CRASH_ADDR_LOW_MAX)) { > >> + crash_max = CRASH_ADDR_HIGH_MAX; > >> + goto retry; > >> + } > >> + > >> pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > >> crash_size); > >> return; > >> } > >> > >> + if (crash_base >= SZ_4G) { > >> + /* > >> + * For case crashkernel=X, low memory is not enough and fall > >> + * back to reserve specified size of memory above 4G, try to > >> + * allocate minimum required memory below 4G again. > >> + */ > >> + if (!high) > >> + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; > >> + > >> + if (reserve_crashkernel_low(crash_low_size)) { > >> + memblock_phys_free(crash_base, crash_size); > >> + return; > >> + } > >> + } > >> + > >> pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", > >> crash_base, crash_base + crash_size, crash_size >> 20); > >> > >> @@ -107,6 +194,9 @@ static void __init reserve_crashkernel(void) > >> * map. Inform kmemleak so that it won't try to access it. > >> */ > >> kmemleak_ignore_phys(crash_base); > >> + if (crashk_low_res.end) > >> + kmemleak_ignore_phys(crashk_low_res.start); > >> + > >> crashk_res.start = crash_base; > >> crashk_res.end = crash_base + crash_size - 1; > >> insert_resource(&iomem_resource, &crashk_res); > >> -- > >> 2.25.1 > >> > > > > . > > > > -- > Regards, > Zhen Lei >